Ring panel air filters contain a single panel of filter media. These MERV 8 ring panel air filters provide between 50% and 70% efficiency for filtering particles between 3 and 10 microns in size (such as mold spores, dusting aids, and cement dust). They also provide 20% or less efficiency for filtering particles between 1 and 3 microns in size (such as legionella, lead dust, humidifier dust, coal dust, and nebulizer droplets).Ring panel and link air filters install into HVAC systems to remove contaminants from the air stream and improve indoor air quality. Unlike standard panel air filters, link filters and ring filters don't require clips or latches to seal them in place. They consist of layered polyester filter media with a metal wire that is heat-sealed around the inside edges to hold the media open. The filter media wraps around the wire to ensure a positive seal when the filter is installed so that air doesn't bypass the filter. These filters typically have a MERV (minimum efficiency reporting value) rating of 8. A filter's MERV rating measures how efficiently it removes contaminants from the air stream based on the size of the particles it can effectively capture. The higher a filter's MERV rating is, the more effectively the filter traps small particles. Ring panel and link air filters are commonly used in commercial buildings, schools, universities, and areas where surface finishing is performed.